diff --git a/lib/tasks/delete_evalution.rake b/lib/tasks/delete_evalution.rake
new file mode 100644
index 000000000..6d01123e0
--- /dev/null
+++ b/lib/tasks/delete_evalution.rake
@@ -0,0 +1,13 @@
+namespace :delete_evalution do
+  desc "delete evaluation"
+  task :delete => :environment do
+    homework = HomeworkCommon.where("id = 844").first
+    homework.homework_detail_manual.update_column('comment_status', 3)
+    student_work_score = StudentWorksScore.where("student_work_id = 28088 and user_id = 9263").first
+    student_work_score.destroy
+    student_work_9203 = StudentWork.where("id = 28088").first
+    student_work_9263 = StudentWork.where("homework_common_id = 844 and user_id = 9263").first
+    student_work_9203.update_column("student_score",91)
+    student_work_9263.update_column("absence_penalty",student_work_9263.absence_penalty+homework.homework_detail_manual.absence_penalty)
+  end
+end
\ No newline at end of file
diff --git a/lib/tasks/homework_evaluation.rake b/lib/tasks/homework_evaluation.rake
index bf5f32dfe..84082eb9b 100644
--- a/lib/tasks/homework_evaluation.rake
+++ b/lib/tasks/homework_evaluation.rake
@@ -60,7 +60,7 @@ namespace :homework_evaluation do
         work_ids = "(" + homework_common.student_works.map(&:id).join(",") + ")"
         homework_common.student_works.each do |student_work|
           absence_penalty_count = student_work.user.student_works_evaluation_distributions.where("student_work_id IN #{work_ids}").count - student_work.user.student_works_scores.where("student_work_id IN #{work_ids}").count
-          student_work.absence_penalty = absence_penalty_count > 0 ? absence_penalty_count * homework_detail_manuals.absence_penalty : 0
+          student_work.absence_penalty = absence_penalty_count > 0 ? absence_penalty_count * homework_detail_manual.absence_penalty : 0
           student_work.save
         end
         homework_detail_manual.update_column('comment_status', 3)